NEW YORK (Reuters) - Aryna Sabalenka passed the biggest test of her title defence against sixth seed Linda Noskova to reach the U.S. Open semi-finals on Tuesday, as Frances Tiafoe survived a five-set thriller and fans awaited an all-American "Battle of the Billionaires."
Second seed Carlos Alcaraz has defied concerns surrounding his long injury layoff and is due up in the final match of the night at Flushing Meadows against eighth seed Ben Shelton.
Sabalenka had not dropped a set this year in New York but found herself pushed to the limit in a 7-6(1) 3-6 7-6(7) win over Noskova, recovering from a mid-match dip in her form to reach her sixth consecutive U.S. Open semi-final.
The highly anticipated meeting between the Czech Wimbledon champion and the U.S. Open titleholder lived up to all expectations, and the Belarusian clinched victory with a gutsy ace from a second serve.
"I just felt at some point in the third set she was definitely serving better than me and putting so much pressure on me, but I'm glad that I kind of, like, threw that thought away and I was able to focus point by point," said Sabalenka, who added to her reputation as one of the hardest players to beat in tiebreaks.
U.S. fan favourite Tiafoe came back from two sets and a break down to defeat his compatriot Alex Michelsen 5-7 3-6 7-5 6-3 7-6(6), flinging his racket to the court in a scene of utter joy after sealing the win with one of his signature forehand strikes.
The marathon match pushed the evening programme to a later start, with another all-American clash due between third seed Jessica Pegula and Emma Navarro, a contest that has quickly been dubbed the "Battle of the Billionaires."
Jessica Pegula, daughter of Buffalo Bills and Sabres owner Terry Pegula, is among three who could overtake Sabalenka as the world number one at this tournament, and she has triumphed in all four of her prior meetings with Navarro, the daughter of billionaire businessman Ben Navarro.
Shelton will need the U.S. fans' full support against fearsome titleholder Alcaraz, who has lost just one of his last 32 matches at the majors, beginning with his title run at last year’s Roland Garros. The American is vying for his second U.S. Open semi-final berth.